Iridium is a precious, silver-white metal and one of the densest materials found on earth.

It's no secret that Iridium is 6 times harder then platinum, 8 times stronger, and resists melting in temperatures exceeding 4,000 degrees Fahrenheit. Superx Iridium spark plugs feature the world’s smaller center electrode,measuring 0.5mm in diameter which offer the superior ignitability without sacrificing durability．Because the majority of sparks are exposed to the air/fuel instead of the metal surface, smaller center will burn fuel more efficiently and delivers higher horsepower and better gas mileage.